Method, device, and program for evaluating shape of casing, and method for correcting casing

Abstract

In a method, a device, and a program for evaluating the shape of a casing and a method for correcting a casing according to the present invention, the methods comprise: a step for acquiring three-dimensional measurement data by three-dimensionally measuring an inner surface shape of the lower half portion and an inner surface shape of the upper half portion; a step for setting a lower horizontal plane processing line relative to a lower attachment surface of the lower half portion and an upper horizontal plane processing line relative to an upper attachment surface of the upper half portion on the basis of the three-dimensional measurement data; a step for setting a plurality of lower reference points on the lower horizontal plane processing line and setting a plurality of upper reference points on the upper horizontal plane processing line; a step for creating three-dimensional assembly data in which the lower half portion and the upper half portion are superimposed on the basis of the three-dimensional measurement data so that the lower reference points and the upper reference points are located on one horizontal plane processing line; a step for calculating a deviation amount between the lower half and upper half portions and a component accommodated in the interior on the basis of the three-dimensional assembly data; and a step for determining whether the deviation amount is within a preset prescribed range.

Description

Casing shape evaluation method, device, and program, and casing correction processing method

[0001] The present disclosure relates to a casing shape evaluation method, a casing shape evaluation device, a program, and a casing correction processing method.

[0002] A steam turbine, as a rotary machine, comprises a casing, a rotor, stator vanes, and moving blades. The casing supports the rotor for free rotation therein, and a plurality of moving blades are fixed to the rotor at intervals in the axial direction. The casing also has a plurality of stator vanes fixed therein at intervals in the axial direction. The stator vanes and moving blades are arranged alternately in the axial direction. The casing is divided into a lower half and an upper half, and is fastened together with a plurality of bolts to form a ring shape.

[0003] During inspection of a steam turbine, multiple bolts are loosened to remove the upper half from the lower half, and the internal components are inspected or repaired. After the inspection or repair of the components is completed, the upper half is attached to the lower half and fastened with bolts. The casing may undergo inelastic deformation, such as creep deformation, due to thermal effects during operation. Patent Document 1, for example, describes a technology for estimating the amount of deformation of the casing.

[0004] International Publication No. 2023 / 162384

[0005] Creep deformation of a casing causes the opposing flanges of the lower and upper halves to curve convexly. Therefore, when attempting to fasten the upper half to the lower half after inspection, the mounting surfaces of the flanges of the lower and upper halves do not properly contact, making fastening difficult. Therefore, it is possible to modify the curved mounting surfaces of the lower and upper halves to make them horizontal. However, while modifying the mounting surfaces of the lower and upper halves improves the contact between the mounting surfaces of the lower and upper halves, it can also shift the relative positions of internal components relative to the lower and upper halves, making it difficult to properly assemble the two. Furthermore, the axis of the bolt hole for fastening the lower and upper halves is tilted relative to the axis of the bolt. If the tilt is too large, the bolt may not fit into the bolt hole.

[0006] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a casing shape evaluation method, device, and program, as well as a casing modification method, that accurately estimate the shape of a casing when the mounting surface of the casing is modified, in particular the inner surface shape of the casing that affects the positional relationship with various components inside the casing.

[0007] In order to achieve the above-mentioned object, the casing shape evaluation method disclosed herein is a method for evaluating the shape of a casing formed by connecting a lower half and an upper half, and includes the steps of: obtaining three-dimensional measurement data by three-dimensionally measuring the inner shape of the lower half and the inner shape of the upper half; setting a lower horizontal plane processing line for the lower mounting surface of the lower half and an upper horizontal plane processing line for the upper mounting surface of the upper half based on the three-dimensional measurement data; setting a plurality of lower reference points on the lower horizontal plane processing line and a plurality of upper reference points on the upper horizontal plane processing line; creating three-dimensional assembly data in which the lower half and the upper half are superimposed based on the three-dimensional measurement data so that the lower reference points and the upper reference points are located on a single horizontal plane processing line; calculating the amount of deviation between the lower half and the upper half and the components housed therein based on the three-dimensional assembly data; and determining whether the amount of deviation is within a predetermined specified range.

[0008] In addition, the casing shape evaluation device disclosed herein is a shape evaluation device for a casing configured by connecting a lower half and an upper half, and includes: a horizontal plane processing line setting unit that sets a lower horizontal plane processing line for the lower mounting surface of the lower half and an upper horizontal plane processing line for the upper mounting surface of the upper half based on three-dimensional measurement data obtained by three-dimensionally measuring the inner surface shapes of the lower half and the upper half; a reference point setting unit that sets a plurality of lower reference points on the lower horizontal plane processing line and a plurality of upper reference points on the upper horizontal plane processing line; an overlay processing unit that creates three-dimensional assembly data in which the lower half and the upper half are overlaid based on the three-dimensional measurement data so that the lower reference points and the upper reference points are positioned on a single horizontal plane processing line; a shape deviation amount calculation unit that calculates the amount of deviation between the lower half and the upper half and the components housed therein based on the three-dimensional assembly data; and a shape determination unit that determines whether the amount of deviation is within a predetermined specified range.

[0009] In addition, the program disclosed herein causes a computer operating as a shape evaluation device for a casing configured by connecting a lower half and an upper half to execute the following steps: acquiring three-dimensional measurement data by three-dimensionally measuring the inner shape of the lower half and the inner shape of the upper half; setting a lower horizontal plane machining line for the lower mounting surface of the lower half and an upper horizontal plane machining line for the upper mounting surface of the upper half based on the three-dimensional measurement data; setting a plurality of lower reference points on the lower horizontal plane machining line and a plurality of upper reference points on the upper horizontal plane machining line; creating three-dimensional assembly data in which the lower half and the upper half are superimposed based on the three-dimensional measurement data so that the lower reference points and the upper reference points are positioned on a single horizontal plane machining line; calculating the amount of deviation between the lower half and the upper half and the components housed therein based on the three-dimensional assembly data; and determining whether the amount of deviation is within a predetermined specified range.

[0010] Furthermore, the casing correction method of the present invention uses the amount of deviation obtained by the casing shape evaluation method to determine whether or not the casing needs to be corrected and the parts that need to be corrected.

[0011] According to the casing shape evaluation method, device, and program, and casing modification method disclosed herein, when the mounting surface of the casing is modified, the inner shape of the casing can be accurately estimated, making it possible to determine whether modification is necessary and which areas require modification.

[0012] FIG. 1 is a schematic diagram showing the internal configuration of a steam turbine. FIG. 2 is a schematic diagram showing the mounting relationship between the lower half and the upper half. FIG. 3 is a schematic diagram showing the deformed shape of the lower half and the upper half. FIG. 4 is a schematic diagram showing the mounting relationship between the lower half and the upper half after corrective processing. FIG. 5 is a block diagram showing a casing shape evaluation device of a first embodiment. FIG. 6 is a flowchart showing processing of a casing shape evaluation method of the first embodiment. FIG. 7 is a side view of a casing for explaining processing for setting horizontal surface processing lines and reference points. FIG. 8 is a cross-sectional view of a casing for explaining processing for setting horizontal surface processing lines and reference points. FIG. 9 is a plan view of a casing for explaining processing for setting horizontal surface processing lines and reference points. FIG. 10 is a side view of a casing for explaining overlay processing on a horizontal surface processing line. FIG. 11 is a block diagram showing a casing shape evaluation device of a second embodiment.

[0013] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, the present disclosure also includes configurations that combine the embodiments. Furthermore, the components in the embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially identical, and those that are within the so-called equivalent range.

[0014] [First embodiment] <Steam turbine> In the first embodiment, a casing shape evaluation method, device, and program will be described as being applied to a steam turbine as a rotary machine. However, the rotary machine is not limited to a steam turbine, and can be applied to a gas turbine, a compressor, etc. Fig. 1 is a schematic diagram showing the internal configuration of a steam turbine.

[0015] In the first embodiment, a steam turbine is used as the rotary machine. However, the rotary machine is not limited to a steam turbine and may be any machine having a configuration in which a rotating body is rotatably supported relative to a stationary body.

[0016] As shown in FIG. 1 , a steam turbine (rotary machine) 10 includes a casing 11 , a rotor 12 , stationary blades 13 , and moving blades 14 .

[0017] The casing 11 has a hollow shape, and the rotor 12 is arranged horizontally inside. The rotor 12 is supported for free rotation about an axis O1 by bearings 21 and 22 provided in the casing 11 (or the foundation of the plant). A plurality of stator vanes 13 are fixed to the inner periphery of the casing 11 at intervals in the axial direction A of the rotor 12. A plurality of moving blades 14 are fixed to the outer periphery of the rotor 12 at intervals in the axial direction A. The stator vanes 13 are arranged along the radial direction R of the rotor 12 and at intervals in the circumferential direction of the rotor 12. The moving blades 14 are arranged along the radial direction R of the rotor 12 and at intervals in the circumferential direction of the rotor 12, and the stator vanes 13 and moving blades 14 are arranged alternately in the axial direction A.

[0018] The casing 11 is provided with a steam supply port 23 at one end in the axial direction A. The steam supply port 23 is connected through a steam passage 24 to a blade row section 25 in which the stator blades 13 and the rotor blades 14 are arranged. The blade row section 25 is connected to an exhaust chamber 26. The casing 11 is provided with a steam exhaust port 27 at the other end in the axial direction A. The steam exhaust port 27 is connected to the exhaust chamber 26.

[0019] High-pressure steam is supplied from a steam supply port 23 through a steam passage 24 to a blade row section 25. The steam passes through the plurality of stator vanes 13 and the plurality of moving blades 14, thereby driving the rotor 12 to rotate via each moving blade 14. A generator (not shown) is connected to the rotor 12, and the generator is driven by the driving force of the rotor 12. The steam that has driven each moving blade 14 is exhausted to the outside from a steam exhaust port 27 through an exhaust chamber 26.

[0020] <Creep Deformation of Casing> FIG. 2 is a schematic diagram showing the mounting relationship between the lower half and the upper half, FIG. 3 is a schematic diagram showing the deformed shapes of the lower half and the upper half, and FIG. 4 is a schematic diagram showing the mounting relationship between the lower half and the upper half after correction processing.

[0021] As shown in FIG. 2 , the casing 11 has a lower half 31 and an upper half 32. The lower half 31 has a plurality of cabin support parts (not shown) around it. The plurality of cabin support parts of the lower half 31 are each supported on a frame by support members (not shown). A lower storage space is provided inside the lower half 31. Meanwhile, the upper half 32 is disposed above the lower half 31. An upper storage space is provided inside the upper half 32. The casing 11 is configured such that the upper half 32 is disposed on the lower half 31 and fastened together with a plurality of bolts (not shown).

[0022] The casing accommodates a turbine 33 therein. The turbine 33 is configured by providing moving blades 14 (see FIG. 1 for both) on the outer periphery of the rotor 12. The turbine 33 is disposed in a lower storage space portion of the lower half portion 31 and an upper storage space portion of the upper half portion 32. The turbine 33 is supported rotatably about an axis O1 by a pair of bearings 34, 35 supported by the lower half portion 31 and the upper half portion 32.

[0023] The casing 11 undergoes creep deformation due to thermal influences during operation. When inspecting the steam turbine 10, the upper half is removed from the lower half. At this time, the lower and upper halves are no longer restrained by the bolts and deform. As shown in FIG. 3 , for example, creep deformation of the lower half 31 is such that the lower mounting surface 41 curves upwardly and convexly, while creep deformation of the upper half 32 is such that the upper mounting surface 42 curves downwardly and convexly. However, creep deformation of the lower half 31 and the upper half 32 is not limited to these deformations. Therefore, when attempting to fasten the upper half 32 to the lower half 31 again, the lower mounting surface 41 and the upper mounting surface 42 do not properly contact each other, making fastening difficult.

[0024] Therefore, the lower mounting surface 41 of the lower half 31 and the upper mounting surface 42 of the upper half 32 are modified. That is, the lower mounting surface 41 of the lower half 31 is machined along the lower horizontal surface machining line L1. The upper mounting surface 42 of the upper half 32 is machined along the upper horizontal surface machining line L2. Here, the lower horizontal surface machining line L1 and the upper horizontal surface machining line L2 are horizontal surfaces that are parallel to the axis O1 of the turbine 33. As shown in FIGS. 3 and 4 , the lower mounting surface 41 of the lower half 31 is machined to form the machined lower mounting surface 43, and the upper mounting surface 42 of the upper half 32 is machined to form the machined upper mounting surface 44. Therefore, the machined lower mounting surface 43 and the machined upper mounting surface 44 of the lower half 31 and upper half 32 can be fastened together by proper contact between them.

[0025] However, when the lower mounting surface 41 of the lower half 31 and the upper mounting surface 42 of the upper half 32 are modified, the lower mounting surface 43 to be machined and the upper mounting surface 44 to be machined are in proper contact, but the positions of the lower half 31 and the upper half 32 and the internal components are misaligned.

[0026] That is, as shown in FIG. 2 , the lower half 31 and the upper half 32 are provided with mating portions 36 and 37 for assembling internal components (e.g., blade rings, etc.). The annular mating portions 36 and 37 are on the same plane perpendicular to the axis O1 of the turbine 33. As shown in FIG. 4 , if the lower half 31 and the upper half 32 are fastened together by bringing into contact a lower mounting surface 43 and an upper mounting surface 44, which are formed by modifying the lower mounting surface 41 of the lower half 31 and the upper mounting surface 42 of the upper half 32, respectively, the mating portions 36 and 37 would be on different planes inclined relative to the axis O1 of the turbine 33. This would prevent internal components (e.g., blade rings, etc.) from being properly assembled to the lower half 31 and the upper half 32, potentially resulting in performance degradation and erosion due to steam leakage.

[0027] As shown in FIG. 2 , the lower half 31 is provided with a support portion 38 that supports the weight of internal components (e.g., a blade ring or an inner casing in the case of a double casing). As shown in FIG. 4 , if the lower mounting surface 41 of the lower half 31 is modified to form a machined lower mounting surface 43, the distance between the support portion 38 and the axis O1 of the turbine 33 will be shortened. This could result in contact between the turbine and the components disposed on the support portion 38 of the lower half 31. Furthermore, if the lower mounting surface 41 of the lower half 31 and the upper mounting surface 42 of the upper half 32 are modified to form the machined lower mounting surface 43 and the machined upper mounting surface 44, the distance between the bottom surface of the lower half 31 and the top surface of the upper half 32 will be shortened. This could result in difficulty in storing components in the storage spaces of the lower half 31 and the upper half 32.

[0028] Furthermore, the lower half portion 31 and the upper half portion 32 are formed with bolt holes through which bolts for fastening the two portions are inserted. The bolt holes are provided in a direction perpendicular to the lower mounting surface 41 and the upper mounting surface 42. When the lower half portion 31 and the upper half portion 32 are fastened together by contacting a lower mounting surface 43 and an upper mounting surface 44, which are formed by modifying the lower mounting surface 41 of the lower half portion 31 and the upper mounting surface 42 of the upper half portion 32, the bolt holes are inclined relative to the lower mounting surface 43 and the upper mounting surface 44. Furthermore, the bolts inserted into the inclined bolt holes are also inclined relative to the lower mounting surface 43 and the upper mounting surface 44. This may prevent the bolts from entering the bolt holes in the lower half portion 31 and the upper half portion 32.

[0029] In this way, the lower mounting surface 41 of the lower half 31 and the upper mounting surface 42 of the upper half 32 are corrected to form the lower machined mounting surface 43 and the upper machined mounting surface 44. When the lower half 31 and the upper half 32 are assembled with the internal components, misalignment occurs between the lower half 31 and the upper half 32 and the internal components. If the misalignment is significant, further correction processing is performed on the lower half 31 and the upper half 32.

[0030] <Shape Evaluation Device> FIG. 5 is a block diagram showing a casing shape evaluation device according to the first embodiment.

[0031] As shown in Figures 4 and 5, a casing shape evaluation device (hereinafter referred to as the shape evaluation device) 50 estimates the positional deviation that occurs when the lower half 31 and the upper half 32 of the casing 11 are assembled with the components after the lower mounting surface 41 of the lower half 31 and the upper mounting surface 42 of the upper half 32 have been corrected, and evaluates whether the amount of shape deviation is such that further correction processing is required.

[0032] 5, the shape evaluation device 50 includes a horizontal surface processing line setting unit 51, a reference point setting unit 52, an overlay processing unit 53, a shape deviation amount calculation unit 54, and a shape determination unit 55. The shape evaluation device 50 is a control device, which is a controller, and is realized by, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit) executing various programs stored in a storage unit using a RAM as a working area.

[0033] Furthermore, the shape evaluation device 50 is connected to a three-dimensional measurement data acquisition unit 61 , an operation unit 62 , an output unit 63 , and a storage unit 64 .

[0034] The three-dimensional measurement data acquisition unit 61 is, for example, a non-contact three-dimensional measurement device. As shown in FIGS. 3 and 4 , the three-dimensional measurement data acquisition unit 61 acquires a three-dimensional image by, for example, using a laser displacement meter to project a slit-shaped laser beam or the like onto the lower half portion 31 and the upper half portion 32 and then using a camera to measure the patterned light. Specifically, when the upper half portion 32 is detached from the lower half portion 31, the three-dimensional measurement data acquisition unit 61 acquires three-dimensional measurement data by three-dimensionally measuring the inner shapes of the lower half portion 31 and the upper half portion 32. Here, the internal shapes include the mounting surfaces 41 and 42, the fitting portions 36 and 37, the support portion 38, the bottom surface 31 a, the top surface 32 a, the bolt holes, and the like of the casing 11 (the lower half portion 31 and the upper half portion 32), as will be described later.

[0035] The three-dimensional measurement data acquired by the three-dimensional measurement data acquisition unit 61 includes lower three-dimensional data on the lower mounting surface 41 and lower inner surface shape of the lower half 31, and upper three-dimensional data on the upper mounting surface 42 and upper inner surface shape of the upper half 32. The three-dimensional data on the lower mounting surface 41 of the lower half 31 and the upper mounting surface 42 of the upper half 32 is, for example, three-dimensional coordinate data on the lower mounting surface 41 of the lower half 31 and the upper mounting surface 42 of the upper half 32. Furthermore, the lower three-dimensional data on the lower inner surface shape of the lower half 31 and the upper three-dimensional data on the upper inner surface shape of the upper half 32 are, for example, three-dimensional coordinate data on the lower internal space shape of the lower half 31 and the internal space shape of the upper half 32. The three-dimensional coordinate data is data on the absolute coordinates of the upper half 32 and lower half 31 relative to a preset origin (X0, Y0, Z0).

[0036] The three-dimensional measurement data acquisition unit 61 is connected to the shape evaluation device 50. The three-dimensional measurement data acquisition unit 61 outputs the acquired three-dimensional measurement data of the inner shape of the lower half portion 31 and the inner shape of the upper half portion 32 to the shape evaluation device 50.

[0037] The horizontal surface processing line setting unit 51 sets a lower horizontal surface processing line L1 for the lower mounting surface 41 of the lower half 31 and an upper horizontal surface processing line L2 for the upper mounting surface 42 of the upper half 32 based on the three-dimensional measurement data. Here, as described above, the lower horizontal surface processing line L1 and the upper horizontal surface processing line L2 are planes along the horizontal direction and parallel to the direction of the axis O1 of the turbine 33. The lower horizontal surface processing line L1 and the upper horizontal surface processing line L2 are planes for processing the deformed lower mounting surface 41 and upper mounting surface 42 of the lower half 31 and upper half 32 into horizontal planes. The lower horizontal surface processing line L1 and the upper horizontal surface processing line L2 are defined by three-dimensional absolute coordinate data. The horizontal surface processing line setting unit 51 outputs the three-dimensional data of the set lower horizontal surface processing line L1 and upper horizontal surface processing line L2 to the reference point setting unit 52.

[0038] The reference point setting unit 52 sets a plurality of lower reference points P11, P12, P13, and P14 on the lower horizontal plane processing line L1 and a plurality of upper reference points P21, P22, P23, and P24 on the upper horizontal plane processing line L2. The number of lower reference points P11, P12, P13, and P14 and the number of upper reference points P21, P22, P23, and P24 are not limited to four. The lower reference points and the upper reference points are set at at least three positions on the lower horizontal plane processing line L1 and the upper horizontal plane processing line L2, spaced a predetermined distance from each other, and are defined by three-dimensional absolute coordinate data from the origin. The lower reference points P11, P12, P13, and P14 and the upper reference points P21, P22, P23, and P24 may be at the same position or at different positions. The reference point setting unit 52 outputs three-dimensional data of the set lower reference points P11, P12, P13, and P14 and upper reference points P21, P22, P23, and P24 to the superposition processing unit 53.

[0039] The overlay processing unit 53 generates three-dimensional assembly data in which the lower half 31 and the upper half 32 are overlaid based on the three-dimensional measurement data so that the lower reference points P11, P12, P13, and P14 and the upper reference points P21, P22, P23, and P24 are located on a single horizontal plane machining line L. Here, the horizontal plane machining line L is set at a position where the lower horizontal plane machining line L1 and the upper horizontal plane machining line L2 overlap. The lower reference points P11, P12, P13, and P14 and the upper reference points P21, P22, P23, and P24 are defined by three-dimensional absolute coordinates. The overlay processing unit 53 generates the three-dimensional assembly data using the three-dimensional absolute coordinates of the lower reference points P11, P12, P13, and P14 and the upper reference points P21, P22, P23, and P24. The overlap processing unit 53 outputs the created three-dimensional assembly data to the shape deviation amount calculation unit 54 .

[0040] The shape deviation amount calculation unit 54 calculates the amount of deviation between the lower half portion 31 and the upper half portion 32 and the components housed therein based on the three-dimensional assembly data. Here, the amount of deviation is at least one of the amount of deviation of the fitting portion between the lower half portion 31 and the upper half portion 32 and the components, the amount of deviation of the radial gap between the lower half portion 31 and the upper half portion 32 and the components, and the amount of deviation of the support portion 38 between the lower half portion 31 and the upper half portion 32 and the components. Note that the amount of deviation may also include the amount of deviation of the bolt holes in the lower half portion 31 and the upper half portion 32. Here, the amount of deviation refers to the length in a three-dimensional direction, the inclination with respect to a three-dimensional direction, etc. The shape deviation amount calculation unit 54 outputs the calculated amount of deviation to the shape determination unit 55.

[0041] The shape determination unit 55 determines whether the amount of misalignment is within a predetermined range. The predetermined range refers to a range of misalignment that allows the lower half 31 and the upper half 32 to be fastened together without contacting the lower half 31 and the upper half 32 with other components and without creating large gaps, simply by modifying the mounting surfaces 41 and 42 of the lower half 31 and the upper half 32 to be horizontal surfaces corresponding to the horizontal surface processing lines L1 and L2, without requiring any other modification, such as modification of the fitting portions 36 and 37 with the blade ring or bolt holes. Note that a misalignment that is so small that it does not require modification to make the mounting surfaces 41 and 42 horizontal surfaces also falls within the predetermined range.

[0042] The operation unit 62 is connected to the shape evaluation device 50. The operation unit 62 can be operated by an operator. When the operator operates the operation unit 62, various command signals can be input to the shape evaluation device 50. The operation unit 62 is, for example, a keyboard or a touch-type display.

[0043] The output unit 63 is connected to the shape evaluation device 50. The output unit 63 outputs the evaluation results of the casing 11 evaluated by the shape evaluation device 50. The output unit 63 is, for example, a monitor or a printer.

[0044] The storage unit 64 is connected to the shape evaluation device 50. The storage unit 64 stores a program that the shape evaluation device 50 uses to evaluate the casing 11. The storage unit 64 also stores the three-dimensional measurement data of the lower half portion 31 and the upper half portion 32 acquired by the three-dimensional measurement data acquisition unit 61.

[0045] <Shape evaluation method> Figure 6 is a flowchart showing the processing of the shape evaluation method for a casing of the first embodiment, Figure 7 is a side view of the casing to explain the processing of setting the horizontal surface processing line and reference point, Figure 8 is a cross-sectional view of the casing to explain the processing of setting the horizontal surface processing line and reference point, Figure 9 is a plan view of the casing to explain the processing of setting the horizontal surface processing line and reference point, and Figure 10 is a side view of the casing to explain the overlap processing on the horizontal surface processing line.

[0046] 5 and 6 , in step S11, the three-dimensional measurement data acquisition unit 61 acquires three-dimensional measurement data by three-dimensionally measuring the inner shape of the lower half 31 when the upper half 32 is detached from the lower half 31. Here, the three-dimensional measurement data is lower three-dimensional data of the lower mounting surface 41 of the lower half 31 and the lower inner shape. As shown in FIG. 7 , the lower three-dimensional data includes at least three-dimensional coordinate data of the lower mounting surface 41, three-dimensional coordinate data of the fitting portion 36 (tilt θ1), three-dimensional coordinate data of the bottom surface 31 a (depth D1 of the bottom surface 31 a), and three-dimensional coordinate data of the support portion 38 (distance D2 to the support portion 38).

[0047] 5 and 6, in step S12, the horizontal surface processing line setting unit 51 sets a lower horizontal surface processing line L1 for the lower mounting surface 41 of the lower half portion 31 based on the three-dimensional measurement data. That is, as shown in Fig. 7, since the lower half portion 31 is curved and deformed in the longitudinal direction, the lower horizontal surface processing line L1 is set for correcting and machining the lower mounting surface 41 of the lower half portion 31. Note that, as shown in Fig. 8, if the lower half portion 31 is also curved and deformed in the width direction, the lower horizontal surface processing line L1 is set for correcting and machining the lower mounting surface 41 of the lower half portion 31.

[0048] 5 and 6, in step S13, the reference point setting unit 52 sets a plurality of lower reference points P11, P12, P13, and P14 on the lower horizontal plane processing line L1. In this case, as shown in Fig. 9, since the lower half portion 31 has lower mounting surfaces 41 on both sides in the width direction, the lower reference points P11 and P12 are set on one side in the width direction, and the lower reference points P13 and P14 are set on the other side in the width direction.

[0049] As shown in FIGS. 5 and 6, steps S21 to S23 are executed in parallel with steps S11 to S13.

[0050] In step S21, the three-dimensional measurement data acquisition unit 61 acquires three-dimensional measurement data by three-dimensionally measuring the inner shape of the upper half 32 when the upper half 32 is removed from the lower half 31. Here, the three-dimensional measurement data is upper three-dimensional data of the upper mounting surface 42 and the upper inner shape of the upper half 32. As shown in FIG. 7 , the upper three-dimensional data includes at least three-dimensional coordinate data of the upper mounting surface 42, three-dimensional coordinate data of the fitting portion 37 (tilt θ2), and three-dimensional coordinate data of the top surface 32a (height D11 of the top surface 32a). However, if a stud remains in the lower half 31 or upper half 32, the shape of the stud may also be measured. Alternatively, the shape of the bolt hole may also be measured.

[0051] 5 and 6, in step S22, the horizontal surface processing line setting unit 51 sets an upper horizontal surface processing line L2 for the upper mounting surface 42 of the upper half portion 32 based on the three-dimensional measurement data. That is, as shown in Fig. 7, since the upper half portion 32 is curved and deformed in the longitudinal direction, an upper horizontal surface processing line L2 is set for correcting and machining the upper mounting surface 42 of the upper half portion 32. Note that, as shown in Fig. 8, if the upper half portion 32 is also curved and deformed in the width direction, an upper horizontal surface processing line L2 is set for correcting and machining the upper mounting surface 42 of the upper half portion 32.

[0052] 5 and 6, in step S23, the reference point setting unit 52 sets a plurality of upper reference points P21, P22, P23, and P24 on the upper horizontal plane machining line L2. In this case, as shown in Fig. 9, since the upper half portion 32 has upper mounting surfaces 42 on both sides in the width direction, the upper reference points P21 and P22 are set on one side in the width direction, and the upper reference points P23 and P24 are set on the other side in the width direction.

[0053] 5 and 6, in step S31, the overlay processing unit 53 generates three-dimensional assembly data in which the lower half 31 and the upper half 32 are overlaid based on the three-dimensional measurement data so that the lower reference points P11, P12, P13, and P14 and the upper reference points P21, P22, P23, and P24 are located on one horizontal machining line L. That is, as shown in Fig. 10, the overlay processing unit 53 generates three-dimensional assembly data in which the upper half 32 is assembled to the lower half 31 so that the lower horizontal machining line L1 of the lower half 31 and the upper horizontal machining line L2 of the upper half 32 coincide on the horizontal machining line L, and the lower reference points P11, P12, P13, and P14 of the lower half 31 and the upper reference points P21, P22, P23, and P24 of the upper half 32 overlap on the three-dimensional absolute coordinates.

[0054] 5 and 6, in step S32, the shape deviation calculation unit 54 calculates the deviation amounts between the lower half 31 and the upper half 32 and the components housed therein based on the three-dimensional assembly data. As shown in Fig. 10, the first deviation amount is the inclination θ1, θ2 of the fitting portions 36, 37, the second deviation amount is the depth (gap) D1a from the horizontal surface machining line L to the bottom surface 31a and the height (gap) D11a from the horizontal surface machining line L to the top surface 32a, and the third deviation amount is the distance (gap) D2a from the horizontal surface machining line L to the support portion 38. Although not shown, the inclination of the bolt holes formed in the lower half 31 and the upper half 32 may be calculated as a fourth deviation amount.

[0055] 5 and 6, in step S33, the shape determination unit 55 determines whether the amount of deviation is within a predetermined range. That is, as shown in FIG. 10, the shape determination unit 55 determines whether the inclinations θ1 and θ2 of the fitting portions 36 and 37 (as a first deviation amount) are within the predetermined range. It also determines whether the depth D1a from the horizontal surface machining line L to the bottom surface 31a and the height D11a from the horizontal surface machining line L to the top surface 32a (as a second deviation amount) are within the predetermined range. It also determines whether the distance D2a from the horizontal surface machining line L to the support portion 38 (as a third deviation amount) is within the predetermined range.

[0056] As shown in FIGS. 5 and 6 , if the shape determination unit 55 determines in step S33 that the amount of deviation is within a specified range (Yes), it outputs in step S34 that no processing is required other than the correction processing for machining the mounting surfaces 41, 42 of the lower half 31 and the upper half 32 to horizontal surfaces corresponding to the horizontal surface processing lines L1, L2, such as correction processing of the fitting portions 36, 37 of the blade ring or bolt holes. Although not shown in FIG. 6 , a determination flow may be added that outputs that no processing is required to correct the mounting surfaces 41, 42 to horizontal surfaces if the amount of deviation is within a predetermined specified value and is significantly smaller than the specified value. On the other hand, if the shape determination unit 55 determines in step S33 that the amount of deviation is not within the specified range (No), it outputs in step S35 that not only the correction processing for machining the mounting surfaces 41, 42 of the lower half 31 and the upper half 32 to horizontal surfaces but also other processing is required, such as correction processing of the fitting portions 36, 37 of the blade ring or bolt holes.

[0057] 11 is a block diagram showing a casing shape evaluation device according to a second embodiment. Note that members having the same functions as those in the first embodiment described above are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0058] As shown in Figure 11, the shape evaluation device 50A includes a horizontal surface processing line setting unit 51, a reference point setting unit 52, an overlay processing unit 53, a shape deviation amount calculation unit 54, a shape determination unit 55, and an inner surface shape estimation unit 71.

[0059] The three-dimensional measurement data acquisition unit 61 acquires three-dimensional measurement data by three-dimensionally measuring the inner shape of the lower half 31 and the inner shape of the upper half 32 when the upper half 32 is detached from the lower half 31. Here, the three-dimensional measurement data (internal shape) acquired by the three-dimensional measurement data acquisition unit 61 includes lower three-dimensional data of the lower mounting surface 41 of the lower half 31 and upper three-dimensional data of the upper mounting surface 42 of the upper half 32.

[0060] The inner surface shape estimation unit 71 estimates lower three-dimensional data of the lower inner surface shape of the lower half portion 31 and upper three-dimensional data of the upper inner surface shape of the upper half portion 32 based on the lower three-dimensional data of the lower mounting surface 41 of the lower half portion 31, the three-dimensional data of the upper mounting surface 42 of the upper half portion 32, and the design data acquired by the three-dimensional measurement data acquisition unit 61. That is, the inner surface shape estimation unit 71 estimates three-dimensional coordinate data (tilt θ1) of the fitting portion 36, three-dimensional coordinate data of the bottom surface 31a (depth D1 of the bottom surface 31a), and three-dimensional coordinate data of the support portion 38 (distance D2 to the support portion 38) based on the three-dimensional coordinate data of the lower mounting surface 41 of the lower half portion 31. Furthermore, the inner surface shape estimation unit 71 estimates three-dimensional coordinate data (tilt θ2) of the fitting portion 37 and three-dimensional coordinate data of the top surface 32a (height D11 of the top surface 32a) based on the three-dimensional coordinate data of the upper mounting surface 42 of the upper half portion 32. In other words, the inner surface shape estimation unit 71 calculates the three-dimensional displacement amount between the design data and deformation data (measurement data) of each mounting surface 41, 42 in the lower half 31 and the upper half 32, and estimates the deformation data (three-dimensional coordinate data) of the fitting portions 36, 37, bottom surface 31a, top surface 32a, and support portion 38 from the design data and the three-dimensional displacement amount of the fitting portions 36, 37, bottom surface 31a, top surface 32a, and support portion 38 in the lower half 31 and the upper half 32.

[0061] That is, as a prerequisite, in the second embodiment, the three-dimensional shapes of the mating portions 36, 37, bottom surface 31a, top surface 32a, etc. of the lower half portion 31 and the upper half portion 32 are not measured. Instead, the three-dimensional shapes of the mounting surfaces 41, 42 are measured and used. Specifically, the estimation procedure is as follows: 1. The three-dimensional data of the mounting surfaces 41, 42 of the lower half portion 31 and the upper half portion 32 is compared with the design data, and the amount of vertical deformation and the amount of change in surface orientation of the mounting surfaces 41, 42 are calculated. 2. The surface orientation of the mating portions 36, 37 is calculated assuming that the change in surface orientation of the mating portions 36, 37 matches the amount of change in orientation of the nearby mounting surfaces 41, 42. 3. The amount of vertical deformation of the bottom surface 31a, top surface 32a, support portion 38, etc. is estimated assuming that the amount of vertical deformation of the nearby mounting surfaces 41, 42 matches the amount of vertical deformation of the nearby mounting surfaces 41, 42. The actual dimensions are determined by adding this amount of deformation to the dimensions of the design data. 4. Calculate the orientation of the bolts and bolt holes, assuming that they are aligned with the orientation of the nearby mounting surfaces 41, 42. 5. Use the results of calculations 2 to 4 above instead of the three-dimensional data of the fittings 36, 37, bottom surface 31 a, top surface 32 a, etc., to evaluate whether the dimensions of the internal shape are within the specified range, as in the first embodiment.

[0062] The horizontal plane machining line setting unit 51 sets a lower horizontal plane machining line L1 relative to the lower mounting surface 41 of the lower half 31 and an upper horizontal plane machining line L2 relative to the upper mounting surface 42 of the upper half 32 based on the three-dimensional measurement data. The reference point setting unit 52 sets a plurality of lower reference points P11, P12, P13, and P14 on the lower horizontal plane machining line L1, and sets a plurality of upper reference points P21, P22, P23, and P24 on the upper horizontal plane machining line L2. The overlay processing unit 53 creates three-dimensional assembly data in which the lower half 31 and the upper half 32 are overlaid based on the three-dimensional measurement data so that the lower reference points P11, P12, P13, and P14 and the upper reference points P21, P22, P23, and P24 are located on one horizontal plane machining line L.

[0063] The shape deviation amount calculation unit 54 calculates the amount of deviation between the lower half portion 31 and the upper half portion 32 and the components housed therein based on the three-dimensional assembly data. At this time, the shape deviation amount calculation unit 54 calculates the amount of deviation between the lower half portion 31 and the upper half portion 32 and the components housed therein based on the lower three-dimensional data of the lower inner surface shape of the lower half portion 31 and the upper three-dimensional data of the upper inner surface shape of the upper half portion 32 estimated by the inner surface shape estimation unit 71. Then, the shape determination unit 55 determines whether the amount of deviation is within a predetermined specified range.

[0064] In the above-described first and second embodiments, the three-dimensional measurement data acquisition unit 61 acquires three-dimensional measurement data for the creep-deformed lower half portion 31 and upper half portion 32, and the shape evaluation device 50 performs various processes based on this three-dimensional measurement data. However, the shape evaluation device 50 is not limited to such processes. For example, the three-dimensional measurement data acquisition unit 61 may acquire three-dimensional measurement data after corrective processing has been performed on the creep-deformed lower mounting surface 41 of the lower half portion 31 and the upper mounting surface 42 of the upper half portion 32, and the shape evaluation device 50 may perform various processes based on the three-dimensional measurement data after corrective processing.

[0065] 5, a shape evaluation device 50 includes a horizontal plane processing line setting unit 51, a reference point setting unit 52, an overlay processing unit 53, a shape deviation amount calculation unit 54, and a shape determination unit 55. The shape evaluation device 50 also includes a structural analysis unit (not shown). The structural analysis unit performs structural analysis based on the three-dimensional measurement data of the lower half portion 31 and the upper half portion 32 acquired by the three-dimensional measurement data acquisition unit 61, and acquires the inner surface shapes of the creep-deformed lower half portion 31 and the upper half portion 32. Note that other processing is similar to that of the first or second embodiment.

[0066] [Effects of the Present Embodiment] The casing shape evaluation method according to the first aspect includes the steps of: acquiring three-dimensional measurement data by three-dimensionally measuring the inner shape of the lower half portion 31 and the inner shape of the upper half portion 32; setting a lower horizontal plane processing line L1 relative to the lower mounting surface 41 of the lower half portion 31 and an upper horizontal plane processing line L2 relative to the upper mounting surface 42 of the upper half portion 32 based on the three-dimensional measurement data; and setting a plurality of lower reference points P11, P12, P13, and P14 on the lower horizontal plane processing line L1 and a plurality of upper reference points P21, P22 on the upper horizontal plane processing line L2. the steps of: setting the lower reference points P11, P12, P13, P14 and the upper reference points P21, P22, P23, P24; creating three-dimensional assembly data in which the lower half 31 and the upper half 32 are superimposed based on the three-dimensional measurement data so that the lower reference points P11, P12, P13, P14 and the upper reference points P21, P22, P23, P24 are positioned on one horizontal machining line L; calculating the amount of deviation between the lower half 31 and the upper half 32 and the components housed therein based on the three-dimensional assembly data; and judging whether the amount of deviation is within a predetermined range.

[0067] According to the casing shape evaluation method of the first aspect, the shape is estimated by calculating the amount of misalignment between the lower half 31 and the upper half 32 and the components housed therein, based on three-dimensional assembly data in which the lower half 31 and the upper half 32 are superimposed so that the lower reference points P11, P12, P13, and P14 of the lower half 31 and the upper reference points P21, P22, P23, and P24 of the upper half 32 are positioned on the horizontal machining line L. Therefore, by accurately estimating the inner shape of the casing 11 when the mounting surfaces 41 and 42 of the casing 11 are modified, it is possible to appropriately determine whether the lower half 31 and the upper half 32 need to be modified and the areas that require modification.

[0068] The casing shape evaluation method according to the second aspect is the casing shape evaluation method according to the first aspect, further comprising the three-dimensional measurement data including lower three-dimensional data on the shape of the lower mounting surface 41 and lower inner surface of the lower half 31, and upper three-dimensional data on the shape of the upper mounting surface 42 and upper inner surface of the upper half 32. This makes it possible to easily calculate the amount of misalignment between the lower half 31 and the upper half 32 and the components housed therein from the three-dimensional measurement data.

[0069] A casing shape evaluation method according to a third aspect is the casing shape evaluation method according to the first aspect, further comprising the step of: the three-dimensional measurement data includes lower three-dimensional data of the lower mounting surface 41 of the lower half 31 and upper three-dimensional data of the upper mounting surface 42 of the upper half 32; and the lower inner surface shape of the lower half 31 and the upper three-dimensional data of the upper inner surface shape of the upper half 32 are estimated based on the lower three-dimensional data, the upper three-dimensional data, and the design data. This reduces the amount of three-dimensional measurement data to be acquired, thereby shortening the processing time.

[0070] A casing shape evaluation method according to a fourth aspect is the casing shape evaluation method according to any one of the first to third aspects, and further includes performing a structural analysis based on three-dimensional measurement data to obtain the inner surface shapes of the creep-deformed lower half portion 31 and the inner surface shapes of the upper half portion 32. This reduces the amount of three-dimensional measurement data to be obtained, thereby shortening the processing time.

[0071] A casing shape evaluation method according to a fifth aspect is the casing shape evaluation method according to any one of the first to fourth aspects, further comprising: the amount of misalignment is at least one of the amount of misalignment of fitting portions 36, 37 between the lower half portion 31 and the upper half portion 32 and the components, the amount of misalignment of radial gaps between the lower half portion 31 and the upper half portion 32 and the components, the amount of misalignment of support portions 38 between the lower half portion 31 and the upper half portion 32 and the components, and the amount of misalignment of bolts and bolt holes fastening the lower half portion 31 and the upper half portion 32. This makes it possible to calculate with high accuracy the amount of misalignment between the lower half portion 31 and the upper half portion 32 and the components housed therein from the three-dimensional measurement data.

[0072] The casing shape evaluation device according to the sixth aspect includes a horizontal plane processing line setting unit 51 that sets a lower horizontal plane processing line L1 relative to the lower mounting surface 41 of the lower half 31 and an upper horizontal plane processing line L2 relative to the upper mounting surface 42 of the upper half 32 based on three-dimensional measurement data acquired by three-dimensionally measuring the inner surface shape of the lower half 31 and the inner surface shape of the upper half 32, and a horizontal plane processing line setting unit 52 that sets a plurality of lower reference points P11, P12, P13, and P14 on the lower horizontal plane processing line L1 and a plurality of upper reference points P21, P22, P23, and P24 on the upper horizontal plane processing line L2. the lower half 31 and the upper half 32 are superimposed based on the 3D measurement data so that the lower reference points P11, P12, P13, and P14 and the upper reference points P21, P22, P23, and P24 are positioned on a single horizontal machining line L; a shape deviation amount calculation unit 54 that calculates the amount of deviation between the lower half 31 and the upper half 32 and the components housed therein based on the 3D assembly data; and a shape determination unit 55 that determines whether the amount of deviation is within a predetermined range. As a result, by accurately estimating the inner shape of the casing 11 when the mounting surfaces 41 and 42 of the casing 11 are modified, it is possible to appropriately determine whether the lower half 31 and the upper half 32 need to be modified and the areas that need to be modified.

[0073] The program according to the seventh aspect includes, in a shape evaluation device 50, 50A for a casing configured by connecting a lower half 31 and an upper half 32, steps of: acquiring three-dimensional measurement data by three-dimensionally measuring the inner shape of the lower half 31 and the inner shape of the upper half 32; setting a lower horizontal plane processing line L1 relative to a lower mounting surface 41 of the lower half 31 and an upper horizontal plane processing line L2 relative to an upper mounting surface 42 of the upper half 32 based on the three-dimensional measurement data; and setting a plurality of lower reference points P11, P12, P13, and P14 on the lower horizontal plane processing line L1 and a plurality of upper reference points P14 on the upper horizontal plane processing line L2. a step of creating three-dimensional assembly data for overlapping the lower half 31 and the upper half 32 based on the three-dimensional measurement data so that the lower reference points P11, P12, P13, P14 and the upper reference points P21, P22, P23, P24 are located on one horizontal machining line L, a step of calculating the amount of deviation between the lower half 31 and the upper half 32 and the components housed therein based on the three-dimensional assembly data, and a step of determining whether the amount of deviation is within a predetermined specified range. As a result, when the mounting surface of the casing is modified, the inner shape of the casing can be accurately estimated, thereby making it possible to determine whether modification is necessary and the parts that need to be modified.

[0074] The casing correction method according to the eighth aspect uses the amount of deviation obtained by the casing shape evaluation method according to any one of the first to fourth aspects to determine whether correction of the casing 11 is necessary and the parts that need to be corrected. This makes it possible to propose an appropriate correction method for the casing 11.

[0075] DESCRIPTION OF SYMBOLS 10 Steam turbine (rotating machine) 11 Casing 12 Rotor 13 Stationary vane 14 Moving blade 31 Lower half 32 Upper half 33 Turbine 34, 35 Bearing 36, 37 Fitting portion 38 Support portion 41 Lower mounting surface 42 Upper mounting surface 50, 50A Casing shape evaluation device 51 Horizontal surface machining line setting unit 52 Reference point setting unit 53 Overlay processing unit 54 Shape deviation amount calculation unit 55 Shape determination unit 61 Three-dimensional measurement data acquisition unit 62 Operation unit 63 Output unit 64 Memory unit 71 Inner surface shape estimation unit L Horizontal surface machining line L1 Lower horizontal surface machining line L2 Upper horizontal surface machining line P11, P12, P13, P14 Lower reference point P21, P22, P23, P24 Upper reference point

Claims

1. A shape evaluation method for a casing formed by connecting a lower half and an upper half, comprising the steps of: obtaining three-dimensional measurement data by three-dimensionally measuring the inner shape of the lower half and the inner shape of the upper half; setting a lower horizontal plane machining line for the lower mounting surface of the lower half and an upper horizontal plane machining line for the upper mounting surface of the upper half based on the three-dimensional measurement data; setting a plurality of lower reference points on the lower horizontal plane machining line and a plurality of upper reference points on the upper horizontal plane machining line; creating three-dimensional assembly data in which the lower half and the upper half are superimposed based on the three-dimensional measurement data so that the lower reference points and the upper reference points are located on a single horizontal plane machining line; calculating the amount of deviation between the lower half and the upper half and components housed therein based on the three-dimensional assembly data; and determining whether the amount of deviation is within a predetermined specified range.

2. A casing shape evaluation method as described in claim 1, wherein the three-dimensional measurement data includes lower three-dimensional data of the lower mounting surface and lower inner surface shape of the lower half, and upper three-dimensional data of the upper mounting surface and upper inner surface shape of the upper half.

3. A casing shape evaluation method as described in claim 1, wherein the three-dimensional measurement data includes lower three-dimensional data of the lower mounting surface of the lower half and upper three-dimensional data of the upper mounting surface of the upper half, and the lower inner surface shape of the lower half and the upper three-dimensional data of the upper inner surface shape of the upper half are estimated based on the lower three-dimensional data, the upper three-dimensional data, and design data.

4. The casing shape evaluation method according to claim 1, further comprising the steps of: performing a structural analysis based on the three-dimensional measurement data to obtain the inner surface shapes of the creep-deformed lower half portion and the upper half portion.

5. A casing shape evaluation method according to any one of claims 1 to 4, wherein the amount of deviation is at least one of the amount of deviation of the fitting portion between the lower half and the upper half and the component, the amount of deviation of the radial gap between the lower half and the upper half and the component, the amount of deviation of the support portion between the lower half and the upper half and the component, and the amount of deviation of the bolt and bolt hole that fasten the lower half and the upper half.

6. A shape evaluation device for a casing constructed by connecting a lower half and an upper half, comprising: a horizontal plane machining line setting unit that sets a lower horizontal plane machining line for a lower mounting surface of the lower half and an upper horizontal plane machining line for an upper mounting surface of the upper half based on three-dimensional measurement data obtained by three-dimensionally measuring the inner surface shapes of the lower half and the upper half; a reference point setting unit that sets a plurality of lower reference points on the lower horizontal plane machining line and a plurality of upper reference points on the upper horizontal plane machining line; an overlay processing unit that creates three-dimensional assembly data in which the lower half and the upper half are overlaid based on the three-dimensional measurement data so that the lower reference points and the upper reference points are located on a single horizontal plane machining line; a shape deviation amount calculation unit that calculates the amount of deviation between the lower half and the upper half and components housed therein based on the three-dimensional assembly data; and a shape judgment unit that judges whether the amount of deviation is within a predetermined specified range.

7. A shape evaluation device for a casing consisting of a connected lower half and an upper half, the device comprising: a step of obtaining three-dimensional measurement data by three-dimensionally measuring the inner shape of the lower half and the inner shape of the upper half; a step of setting a lower horizontal plane machining line for the lower mounting surface of the lower half and an upper horizontal plane machining line for the upper mounting surface of the upper half based on the three-dimensional measurement data; a step of setting a plurality of lower reference points on the lower horizontal plane machining line and a plurality of upper reference points on the upper horizontal plane machining line; a step of creating three-dimensional assembly data in which the lower half and the upper half are superimposed based on the three-dimensional measurement data so that the lower reference points and the upper reference points are positioned on a single horizontal plane machining line; a step of calculating the amount of deviation between the lower half and the upper half and components housed therein based on the three-dimensional assembly data; and a step of determining whether the amount of deviation is within a predetermined range.

8. A casing correction processing method that uses the amount of deviation obtained by the casing shape evaluation method described in any one of claims 1 to 4 to determine whether or not correction processing of the casing is necessary and the areas that require correction.

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